WATKINS GLEN, N.Y. — Tony Stewart pulled out of the NASCAR race at Watkins Glen Sunday, 12 hours after the three-time champion struck and killed a sprint car driver who had climbed from his car and was on the darkened dirt track trying to confront Stewart during a race in upstate New York.

Greg Zipadelli, competition director for Stewart-Haas Racing, said at a news conference that Stewart “feels strongly” about not competing Sunday following the death of Kevin Ward Jr. The decision was an about-face for the organization, which initially said Stewart would be behind the wheel of his No. 14 Chevrolet when the green flag waved.

“We gave Tony some time to sleep on it. He feels strongly this is the right thing to do,” Zipadelli said. “All you can do is what you feel is right, and we feel this is right. We get through today and do it the best we can as a group.”

In a statement, Stewart said the crash has been “emotional” for all involved.

“There aren’t words to describe the sadness I feel about the accident that took the life of Kevin Ward Jr.,” he said.

The crash happened Saturday night at Canandaigua Motorsports Park, a dirt track and an extracurricular race for a driver of Stewart’s stature. Stewart frequently races in the events as a hobby to the side of the big-money NASCAR races.

Ward, a 20-year-old driver, had crashed following a bump with Stewart one lap earlier. Ward and Stewart were racing side-by-side for position as they exited a turn. Ward was on the outside when Stewart, on the bottom, seemed to slide toward Ward’s car and crowd him toward the wall. The rear tire of Stewart’s car appeared to clip the front tire of Ward’s car, and Ward spun into the fence.

Video showed Ward walking from his crashed car onto the racing surface as cars circled by, and, as he gestured at Stewart’s passing car, he was struck. Ward was standing to the right of Stewart’s familiar No. 14 car, which seemed to kick out from the rear and hit him.

“The next thing I could see, I didn’t see (the other driver) anymore,” witness Michael Messerly said. “It just seemed like he was suddenly gone.”

Authorities questioned Stewart once on Saturday night and went to Watkins Glen to talk to him again Sunday. They described him as “visibly shaken” after the crash and said he was cooperative.

On Sunday, Ontario County Sheriff Philip Povero said that criminal charges have not been ruled out, but that investigators also don’t have any evidence at this point in the investigation to support criminal intent.

“Stewart is free to go about his business,” Povero said.

The sheriff renewed a plea for spectators to turn over photos and videos of the crash. He said cars on the track were traveling around 30-35 mph at the time Ward was struck. Investigators were reconstructing the accident and looking into everything from the dim lighting on a portion of the track to how muddy it was, as well as if the dark firesuit Ward was wearing played a role in his death.

Getting out of a wrecked car to confront another driver is common in almost every series. Wrecked race cars can rarely be driven off the track, and the driver has to get out to find his way back to either the pits or the garage. It creates ample opportunity for angry confrontations.

Stewart has had a few of his own, and everyone from mild-mannered Jeff Gordon to ladylike Danica Patrick has erupted in anger on the track at another driver. The confrontations are part of the sport’s culture: Fans love it and cheer wildly from the stands. They love the bumping, the banging and the bickering.

Driver Cory Sparks, a friend of Ward’s, was driving in Saturday night’s race and was a few cars back when Ward was killed.

“The timing was unsafe,” he said of Ward’s decision to get out of his car to confront Stewart. “When your adrenaline is going, and you’re taken out of a race, your emotions flare.”

The crash Saturday came almost exactly a year after Stewart suffered a compound fracture to his right leg in a sprint car race in Iowa. The injury cost him the second half of the NASCAR season. Stewart only returned to sprint track racing last month, and won in his return, at Tri-City Motor Speedway in Michigan.

The broken leg cost him the entire second-half of last season and sidelined him during NASCAR’s important Chase for the Sprint Cup championship. Stewart wasn’t cleared to get back in a race car until February, the day the track opened for preparations for NASCAR’s season-opening Daytona 500 began.

“Everybody has hobbies,” he said last month.

“That’s what I like to do when I have extra time. I don’t think there is anything wrong with doing it. I feel like there are a lot of other things I could be doing that are a lot more dangerous and a lot bigger waste of time with my time off do than doing that.”

Among Stewart’s many business interests is his ownership of Ohio dirt track Eldora Speedway, and his stake in Stewart-Haas Racing, which fields cars for Stewart, Kevin Harvick, Kurt Busch and Patrick.

The site of Saturday night’s crash is the same track where Stewart was involved in a July 2013 accident that seriously injured a 19-year-old driver. He later took responsibility for his car making contact with another and triggering the 15-car accident that left Alysha Ruggles with a compression fracture in her back.